Introgression of B-genome chromosomes in a doubled haploid population of Brassica napus  B. carinata Z.K. Navabi, I.A.P. Parkin, J.C. Pires, Z. Xiong, M.R. Thiagarajah, A.G. Good, and M.H. Rahman Abstract: The Brassica B-genome species possess many valuable agronomic and disease resistance traits. To transfer traits from the B genome of B. carinata into B. napus, an interspecific cross between B. napus and B. carinata was performed and a doubled haploid (DH) population was generated from the BC2S3 generation. Successful production of interspecific DH lines as identified using B-genome microsatellite markers is reported. Five percent of DH lines carry either intact B- genome chromosomes or chromosomes that have deletions. All of the DH lines have linkage group J13/B7 in common. This was further confirmed using B. nigra genomic DNA in a fluorescent in situ hybridization assay where the B-genome chromosomes were visualized and distinguished from the A- and C-genome chromosomes. The 60 DH lines were also evaluated for morphological traits in the field for two seasons and were tested for resistance to blackleg, caused by Leptos- phaeria maculans, under greenhouse conditions. Variation in the DH population followed a normal distribution for several agronomic traits and response to blackleg. The lines with B-genome chromosomes were significantly different (p < 0.01) from the lines without B-genome chromosomes for both morphological and seed quality traits such as days to flowering, days to maturity, and erucic acid content. Key words: Brassica napus, Brassica carinata, B genome, introgression, SSR markers, cytogenetics, GISH, agronomic traits. Re ´sume ´: Les espe `ces a ` ge ´nome B au sein du genre Brassica posse `dent plusieurs caracte ´ristiques agronomiques et re ´sis- tances a ` des maladies utiles. Pour transfe ´rer ces caracte ´ristiques du ge ´nome B du B. carinata a ` celui du B. napus, un croi- sement interspe ´cifique entre le B. napus et le B. carinata ae ´te ´ re ´alise ´ et une population d’haploı ¨des double ´s (HD) a e ´te ´ ge ´ne ´re ´e a ` partir de la ge ´ne ´ration BC2S3. Le succe `s dans la production de ligne ´es HD interspe ´cifiques a e ´te ´ ve ´rifie ´ en em- ployant des microsatellites spe ´cifiques du ge ´nome B. Cinq pourcent des ligne ´es HD portaient soit des chromosomes intacts du ge ´nome B ou des chromosomes ayant des de ´le ´tions. Toutes les ligne ´es HD avaient en commun J13/B7. Ceci a e ´te ´ confirme ´ en employant l’ADN ge ´nomique du B. nigra lors d’une hybridation in situ en fluorescence ou ` les chromosomes du ge ´nome B ont e ´te ´ visualise ´s et distingue ´s de ceux des ge ´nomes A et C. Ces 60 ligne ´es HD ont e ´galement e ´te ´e ´value ´es pour leurs caracte ´ristiques morphologiques au champ pendant deux saisons de me ˆme qu’en serre pour leur re ´sistance a ` la jambe noire, cause ´e par Leptosphaeria maculans. La variation au sein de la population de ligne ´es HD pre ´sentait une distri- bution normale pour plusieurs des caracte ´ristiques agronomiques et la re ´sistance a ` la jambe noire. Les ligne ´es avec des chromosomes du ge ´nome B e ´taient significativement diffe ´rentes (p < 0,01) des ligne ´es sans chromosome du ge ´nome B tant pour les caracte `res morphologiques (floraison, maturite ´) que les proprie ´te ´s des graines (contenu en acide e ´rucique). Mots-cle ´s : Brassica napus, Brassica carinata, ge ´nome B, introgression, marqueurs SSR, cytoge ´ne ´tique, GISH, caracte `res agronomiques. [Traduit par la Re ´daction] Received 26 October 2009. Accepted 22 April 2010. Published on the NRC Research Press Web site at genome.nrc.ca on 20 July 2010. Corresponding Editor: P. Gustafson. Z.K. Navabi, 1 M.R. Thiagarajah, and M.H. Rahman. Department of Agricultural, Food and Nutritional Science, 4-10 Agric/Forestry Centre, University of Alberta, Edmonton, AB T6G 2P5, Canada. I.A.P. Parkin. Agriculture and Agri-Food Canada, Saskatoon Research Centre, Saskatoon, SK S7N 0X2, Canada. J.C. Pires and Z. Xiong. Division of Biological Sciences, 371 B Life Science Centre, University of Missouri, Columbia, Missouri, 65211-7310, USA. A.G. Good. 2 Department of Biological Sciences, G-425 Biological Sciences Building, University of Alberta, Edmonton, AB T6G 2E9, Canada. 1 Present address: Agriculture and Agri-Food Canada, Saskatoon Research Centre, Saskatoon, SK S7N 0X2, Canada. 2 Corresponding author (e-mail: allen.good@ualberta.ca). 619 Genome 53: 619–629 (2010) doi:10.1139/G10-039 Published by NRC Research Press